Today guests joining your meeting via Chrome can view screen you share, if they want to share their screens with you then they will need to install the Teams app for Windows or Mac. No login is required, the desktop app acts as a meeting client, much like most other apps need so kind of install.

Support for more capabilities in browsers is in the roadmap, as indicated above.

I don't know how long it has been available, but at lease since Dec 13, 2018. Unfortunately, the experience seems to be hit or miss. It worked for me, but doesn't work for two others.

The experience for me is when I click share screen in Teams web, I was prompted to install the plugin., I did so, and was able to share my screen. The experience when it failed is that when they click share screen, they are told screen share isn't supported in their browser (even though they were using Chrome), but they can install Teams desktop which will allow them to share their screen.

We haven't tracked down the "secret" to making this work for all Chrome users, but I am hopeful I will find it.

@Roy Faltesek it'll fix in time. This feature has been in Microsoft's testing cycles for a good while to ensure it reaches the quality mark for widespread deployment. If one of these accounts is in a tap ring it may have the feature. From what I can tell it hasn't started deployment outside tap yet.